this looks like a good bet: http://www.scan.co.uk/products/26-i...920x1200-40001-ACR-300cd-m-5-ms-Speakers-VESA - Native res of 1920x1200 - 2ms response time (brilliant for gaming)
Go as big as you can afford. I have a 30" screen and I'm already contemplating a second monitor. Occasionally you can still pick up a Dell 3007WFP-HC from eBay. Well worth the money.
I use this: http://www.overclockers.co.uk/showproduct.php?prodid=MO-001-HS&groupid=17&catid=1120&subcat= For the money, and what it does, you can't go wrong. You could probably find it cheaper elsewhere too.
The Dell U2711 is a great screen. IPS and high pixel density 2560x1440 resolution. Also supports 30bit color.
I like this company's monitors. They're priced well, but I can't speak for how well they perform when compared to other monitors (because I don't have much to compare to ).
Hannspree ST251 25" LCD Freeview Full HD 1920x1080 £159.99 delivered at eBay / ebay outlet Ebuyer http://www.hotukdeals.com/deals/hannspree-st251-25-lcd-freeview-ful/745566
The Dell 24" UltraSharp UC2711 is a beat of a screen. It will cost you roughly $1000.00 USD (sorry, don't know the conversion), but man are they nice screens. I'm a graphic designer and have the 24" version at work and, wow. Incredibly accurate colors, very sharp pixels, and has a great design. It also comes with a wide variety of inputs so you can hook up a DVD player, Xbox 360, etc. and has a built in card reader on the left bezal, which is a big plus for me. tl;dr: the Dell UC2711 LCD monitor is an awesome, but expensive 27" monitor. You won't be sorry you got it, though if you can afford it!